Neurostimulator Test

Hello!
My dad just got the neurostimulator put in today for a test run to see if this is a good option for him to get it put in permanently. This is his final hope because he is in a lot of back pain and they told him that surgery is not an option. I was wondering if anyone else has had this procedure done because he is in alot of pain. I think the pain right now is from the incisions that were made when inserting the leads. How long does it take for that to heal? Also, the neurostimulator seems to fluctuate dramatically at times and he will all of a sudden yell because of the increasing impulses. I just need some advice that I can give to him on testing the device and on how to control the device and the impulses better. Thank you so much in advance!